Actualité sur la vitamine K

Latest data on vitamin K

Abstract

The difficulty of quantifying vitamin K levels and determining the number of active molecules long impeded in investigations into the metabolism and physiological function of vitamin K. In the last ten years, since gamma carboxylation was first demonstrated, studies have essentially focused on: – vitamin K sources and requirements: the composition of foods and requirements with respect to molecules with vitamin K activity are beginning to be known; – vitamin K and bone: the role of osteocalcin in bone mineralization and its association with vitamin K have been studied, particularly in elderly subjects; – hemorrhagic disease of the newborn: after a number of controversies, it is now generally accepted that prophylactic treatment of all newborns should be systematic, and repeated for breast-fed infants. Vitamin K should be administerted orally except in cases of malabsorption. However, a number of essential questions remain unanswered, such as the precise role played by certain carboxyproteins (bone carboxyprotein or Gas6) and, in particular, the choice of markers for the accurate evaluation of vitamin K status in humans.